Improvement in plane angulomettrs



`declare that the following1 is ajfull andl exactv of the axis of the pendulum and its bearings.

- horizon. y To enable others skilled in the art to make have upon their tops a portion` of a surface of v length thisl portion of the spherical surface v degrees. l

sixty degrees.` In the center of this spherical l and by the longitudinal lines Z Z-thirty de- Fig. 2 and marked P.

UNrTEP STATES PATENT f @Finca ELI TIIAYER, OF lVORCESTER, lllASSAl'IUSETTS.

kHVIPROVEIVIEN'I' IN'PLANE ANGULQMETERS.

v Spcciicalion forming;- part ofjlmitcrs Patent No. 36,3 Il?, dated August 2li, 1362.

To all whom it may concern,.- l V I Be it known-that ,1; ljlnr THAYER, of Worcester, inthe count' of Worcester and State of Massachusetts,v raveinvented a new and'` improved instrument for ascertaining the level ,of plane surfaces or their angle of inclination to the horizon fornautical, astronomical, Inechanical, and militariy uses; and I do hereby description thereof, reference being had to the accompanying dra ings, a'ndvto' tihe letters of Areference marked t i'eon., y .Figure .1 represen saside elevation. Fig. 2 represents a side elevation of the pendulum and quadrant. Fig. '3 represents a. side View and use my invention,I will proceed tovdescribe its construction and operation.

In the drawings, Fig. 1, A is the base'of the instrumentand may consist of wood or metal. It is of uniform thickness and its surfaces are plane. Its thickness should be such as to make it firm and'strong. Upon this base there are erected four supports-two of which are se'e'n in Fig. 1, marked B B. These supports asphere, as seen in Fig. l1, marked C.' .In

should be not less than one hundred andeighty Its width should be not less than surface is an opening bounded bythe meridianal lines m lm--ninety vdegrees on eachgrecs on each. This'space, inclosed as above described, is to allow the longitudinal and meridianal motions of the top ofthe pendulum bearing the graduated quadrant, as shown in From zero on the-meridianal lines m in to a the pole of the sphere is ninety degrees, and

from zero on the same lines, to the opposite pole is ninety degrees. The poles a a are in the same straight line with the bearings s s of the axis E, (shown in Fig. 3,).and are in the same plane with the transverse bearing C, in

the niiddleofxthe axis, and of the knife-edgey (l, which is the centerofl the meri'dianal oscillation ofthe pendulum P, (shown in Fig. 2,) while. the bearings s s or their knife-edges b b (sh'own'in' Fig. 3) are the extremities of the axis of its longitudinal oscillation.

The axis E should bemadeof metahaud its bearing amlkuile-cdges vshould be of steel, as should also the bearings s s and' the knifeedge d.- Between the points g and h ou the pendulum, as shown i'n Fig; 2, -is an open space or mortise extendingthrough the'same, as shown at the' letter` ol of Fig. 1. The width and depth of this space is such as to allow the axis E vto pass through the pendulum which vibrates thereon in meridianal lines. The center of .this Vibration is" the bearing c andthe knifeed'g'e d of the pendulum, Fig; 2.

Q is a qu'adranugraduated and attached to the top of they pendulum in the same plane with the poles a a. This quadrant measures the angles of elevation ordepre'ssion of the plane on which the instrument is placedin-the meridianal direction, orthe dircctiouof the axis by the degrees marked upon the quad rant. Italso shows the angles., of depression or elevation of the same plane in the longitudinal direction, or inthe direction perpenv v dicular to the axis by its positionon the `lona gitudinal line Z. l. I

I is an index, (shown in'Fig1',) whichindientes angles'oi'elevation or depression on the. scales n a of thev meridianal lines m m, in the same way as the quadrant does byits own scale. A

To show the operation of this instrument, (Which'may be called the plane angulome'- ter, since it measures the angles which planes "make with the horirou,)` suppose that the'end L of the platforni-A, Fig. 1, is elevated, for example, tendogrees, the' ball of the pendulum u, Fig. 1;, would swing ten degrees toward a point half-way between k and k, while thequadrant Q would move in the opposite direction and rest on the mark of ten degrees on the longitudinal line ll; or suppose the front side of the platform orbuse A to be eleinstead of three bearings, as4 in the drawings4 Possibly, also, a cylindrical surface mighlgfor ce1-tai n purposes, be substituted for the spherical, by making the index I movable on the.

pendulum, so as to allow thelongitudinal motion, and by dispensing with the quadrant. In this'case the longitudinal degrees would be marked `upon the index, while the others would be marked, as in Fig.1, upon the edges or periphery (in that cas) of a cylinder. I do not therefore confine myself tothe partielllar method'of construction exhibited in the accompanying drawings, but intend to include -ail methods involving the same general plan and accomplishing thel saine results in myv specitications.

`Having thus described my invention and having shown its construction and operation, what I claim as my invention, and desire to secure by `Letters Patent, s-A j IThe pendulum moving upon three or more bearings in the same plane and carrying nponits top a graduated are, audits combination with the spherical surface and the opening therein, substantially as set `forth and described'in the accompanying specifications and drawings, and' for thepurposes indicated. i

i ELI TIIAYER. l Witnesses:

JOHN S. HoLLINesHam,

D, ROWLAND. 

